Process of treating petroleums



Juf)t I?, 1928 l W'.v W. GARY PRocEsfs off TREATING PETRoLEUMs Filed' June '7, 1926v Han/ALT Cnkao/v WA x Hamme/NCM.

g2 504 Darm fh rre-- PatentedA July 17, 1928.

UNITED STATES 1,677,440 PATENT GFFICE.;

WRIGHT W.' GARY, 0F LOS ANGELES, CALIFORNIA, ASSIGNOR 0F ONE-HALF v'.l() CHARLES 0. MIDDLETON, F LOS ANGELES, CALIFORNIA.

PROCESS 0F TBEATING PETROLEUMS.

Application led June 7, 1926. Serial No. 114,078.

This invention relates to the treatment of.

' 15 that these compounds," are readily subject to oxidation, decomposition or polymerization;

'the presence of theseI compounds is the chief cause for the inferiority of products made fromoils, shales, or petroleums ofunstable or impure nature.4 Sulfur and sulfur compounds, which. themselves are'oils or oil soluble, are recognized as one group of objectionable impurities the removal of which is highly desirable.

The characteristics ofsulfurcompounds in petroleum/oils, and similar substances obtaned/v from the various oil fields2 such as Canada, Ohio and California, it 1s found,

areto some extent similar, though marked 3v b" chemical differentiation. In.' fact the 'ominant characteristic of all these surfur compounds in whatever combination they may be present, is their ready susceptibility to oxidation with decomposition, liberation or separation. I have discovered that ,petroleum oils, shales and other organic substances may therefore be freedcompletely of their sulfur content or constitutents and the pure oils of stable character may be produced from petroleums, shales, or organic l .A j, l. substance which by reason of the sulfur con- 3,1.,stitu'tents are 'impure and unsta le.

There are'certam other compounds, ho ever, conf' l tained in petroleum oils, shales and other ory4 5 ganic substances, which after a period of IstandingL undergo oxidation and which eventually precipitate as 'insoluble residues or resinous compounds the nature of which are not [yet .definitely f established. In gaso- Llinefkerosene and distillatesof all natures,

' 4polymferize and darkenfjthel-Loil y with some oils or substances containinglthese compounds j 55.", by the usual sulfuric' acidjjvor irijodifiedtmetho'ds, removes some of them, but there are others which do not respond to these treatments and which consequently are notremoved, their presence in the oil then causlng the undesirable oxidation, polymerizatlon, precipitation lor darkening. Furthermore the sulfuric acids or modified treatments produce acid sludges which are unfit for any purpose, 'except erhaps as fuel, and 1n most cases are there ore waste.

I find that the petroleum oils and their products may be primarily treated to expel the compounds which render the oil naturally impure, without the formation of acid sludge, and due to the'lack of acidity these 'compounds may be readily recovered and are of commercial value. This is of great importance, especially in the case of making lubricating brlght stpck from an impure and asphalt base crude. By ordinary sul- 73 'furie acid or modified treatments to remove the asphalt, tars, etc., the losses .due to acid sludge are so large that the operation is practically uncommercial those losses in some cases being as high as 60% of the original stock treated. Also very sli ht sulfur removal is effected givin the 'shed lubricating oil secondary uahty, due to unstabilit'y. Cracking stock 1n particular ma be-purled by removing those compoun and constituents which render the oil impure and unstable and which decompose in cracking forming undesirable impure compounds zolefines, di-olefines, mercaptans) of foul odor and of very unstable nature. The removal of these newly formed impurities and objectionable compounds requires extensive processing in order to improve the cracked products sufficiently for sale, and again the losses due to acid sludge are lar e. I find that by preliminary urifying a crac ing stock,1 the stock, .w en Vsubsequently cracked, yields converted products of superior quality, good odor and stable nature. v

One of the objects of this invention, therefore, is to provide asmple and economical process by which stable, pure products may be manufactured, without acid sludge losses, and with formation -ofbyproducts of commercial value'. 105 Further objectswill appear from the de-y vtail description in connection with the alccompanying drawings, in which: y iFigure *1 is a diagram of an apparatus; adapted to perform-,the process 'embodying 110 `of organic nature and naturally contained in petroleum oils .and shales, which .render them impure, are susceptible of conversion into, either com unds which .are the orl ment.

complished b ganic insoluble omologues of those im-A pure or undesirable compounds, or into nucleus compounds minus the impure ele- The former conversionl results inl thesey converted compounds being pre-V cipitated from the substance or liquidv from which they are removable by any well known means, as by filtration, or by centrifugin while the latter group remain as the puri ed nucleus compounds in the substance or liquid. These conversions are accontrolled oxidation suicient to comp ete the chemical reactions desired but not strong enough to give detrimental el'ects to the substance, namely ma- 'or'decomposition of the nucleus compounds including dehydrogenation. -This is mostadvantageously brought about by the use of concentrated or 'diluted nascent oxygen,

. which is caused to evolve from an oxidizing general as a group react as gas, such as the gaseous anhydride of all oxidizing acid or from activated oxygen. The active or nascent oxygen generated combines with the sulfur impurity forming sulfur' dioxide and at the same time actin upon the undesirable compounds contain in the substance or oil to oxidize or convert them into their insoluble homologues causmg separation byprecipitation. I have found that any anhydride of an oxidizing ac1d may be' used to effect the purpose of the lnvention provided that the substance to be treated and the gas used is absolutely dry or anhydrous and that the oxidizing agent is kept in a gaseous state. v

.fin example of this is the action of an ox1d1z1ng gas on the type of sulphur compounds found. I. In Ohio petroleum called di alkyl' sulphides. Y

Their general formula is:

(0.a..+17 |sd Or pentyl sulphide (an example) (camas or c`n\ s S can/ omomcmomom/ When properly oxidizedf @mmHg-geanen.. Consequently the difi alkyl vsulphidesV in CHJCHlCHiCHaCH, 0l'

pounds are found to be slightly different inl chemical formula, 'as a grou called thiophanes. Their general formu a is:

Or Heptyl thiophane- (an example).

f om-om-on/ and when oxidized properly,

C'IHMS Oa- 01H14 S0: Consequently the thiophanes in general as a group react as a o.n|.s+o,o.m.+so

V. When mercaptans are present in oil such as' 1n cracked o1l and'Russian oil, the reactlon 1s oni.. ,sa 0,- canal+ so,

forming an alcohol or aldehyde, neither of which is detrimental.

Referring to Example I, the product after desulphurizing is CnHzm;2 or a paraiiin, and in Example II (LI-I2.l or a naphthene. These compoundsare stable and are the mainv constituents of pure oils. Example III shows the formation naphthenes and Example V either paraliines or alcohols. If alcohols are formed they are of great benefit as fuels and are not detrimental in any oil being very stable.

One of the oxidizing agents which can be conveniently employed is sulfuric anhy` dride (SO3); the oxidization is then effected to the following equations:-

I (1) .(cannes@Slowakei-aso.

In using sulfuric anhydride special precautions must be used. namely that the lgas is dry or anhydrous, and alsosthat thetemperadensation of sulfuric anhydride during its passage through the treater, for in the 'event that condensation takes place the time factor governing the degree of oxidization' is suiiciently increased to cause dehydrogenation of the hydrocarbon compounds with the resultant formation of water which combines with the sulfuric anhydride making sulfuric acid. Sulfuric acid, or any acid, is detrimental from both'a chemical and economicall standpoint. From a chemical standpoint esters of the acid are formed, which are partially soluble inthe substance resulting in 'animpure finished product, while from an pounds, will decompose, either wholly or only partially, liberating an oxygen atom or molecule, which in the nascent or active state exercises great chemical activity upon the substance and oxidizes those compounds thereof which make it im ure. An example of such an agent is the a ore-mentioned sulfuric anhydride, (S03), in gaseous state. This compound boils at 112.6 F. Therefore, when using this gas, the temperature of the substance or oil to be treated should be above that temperature at which the sulfuric anhydride would boil, or above which this gas or any other gas used for the purposes of this invention, would condense. A temperature of say 140 F., or ab0ve,.I.find, is suitable for treating. oils when using sulfuric anhydride. If the temperature falls below that 'at which the oxidizing agent would remain a gas, condensation of this agent would occur, with the result that the strong oxidizing action of the condensed S03, would remainin the oil or substance for a longer period of time causing dehydrogenation of the substance with the resultant formation of water, and the sulfuric anhydride combiningwith the water thus formed, forms sulfuric acid," thus:

la compound which I wish to avoid at all a sludge of little or noe 'platinum black Vmanufacture of `On the other hand, exceedingly high temperatures must also be avoided, because of the dehydrogenation upon the substance and the conse uent formation of lWater. While airor mo ecular oxygen alone exerts an action upon the oil, it is not complete, and requires hi her temperatures than can be used beneficia y. Therefore, I may use, as another oxidizing gas, active or ozonized air or oxygen. The anhydrpus gas used by me as a constitutent in the process of oxidizing the undesirable bodies, compounds or constitutent of and in the oil, is introduced into and through the body of the oil, which is maintained at the proper temperature.

If for economic reasons, sulfur trioxide is manufactured by the passing of sulfur dioxide and dried air in the well known manner, over heated spongy platinum or such as is employed in the sulfuric acid by the contact process, the resultant gas is introduced into the treater as sulfur trioxide plus air minus its oxygen content, the ox gen having been used in converting the sul ur dioxide to the trioxide, The air minus its oxygen content is then a diluent to the active gas and is beneficial to the extent that the diluent controls the activity of the oxidizing agent.

portion of the gas reactsy upon the other I undesirable compounds in the oil, subject to oxidation, and precipitate them from theoil. Any form of apparatus may be used,

'continuous or batch, examples of which arc shown in the accompanying drawings, it is to be understood, however, that this invention is not limited to any particular apparatus, and that aparatus has simply' been shown to illustrate the process. It will, therefore, be noted that the drawings are diametrical in form, but it will be understood that valves and other accessories will be provided wherever indicated and wherever required.

Referring now to Fig. 1, which illustrates one embodiment of this invention employing sulfuric anhydride, the operation will be as follows:

Starting from the gas holder 1 which contains a proper mixture of sulfur dioxide and air, this is conducted to a drier 2 to remove moisture. From the drier the mixture passes to a catalyst 3 which is in this case a platinum black tube maintained at a temperature of 600 Fl where' the sulfur dioxide and oxygen of the air combine and which acts to absorb the unconverted sulfuric` anhydride. The -sulfur dioxide and air passes to a charcoal absorber 6 where it is absorbed `and the air allowed to exit through an air vent 7. By manipulation of the valves 8 and 9 between the treater and the scrubber fresh air can be forced first through the scrubber and dried out and then through the charcoal absorber which is lno'w hot and gives up its sulfur dioxide. This is continued until all thesulfur dioxide is removed from the absorber, the sulfur dioxide and fresh air passing into the gas holder for subsequent utilization. The dried oil is drained -through the medium 'of valves and passed to the filter 10, from which it can -be drawn. The treater is supplied from impure oil storage 11 from which it is delivered to the treater by a pump 12 as shown. The treater may be of any conventional type used 'l in the' refining of petroleum, and is suitably provided with a conical bottom 13 for the collection and accumulation of the products precipitated as a result of the actions occurring in the oil. The treater as a Whole is suitably steam-jacketed for maintaining the temperatures required in treating. The oxidizing gas passes through the top of the treater and is conducted by apipe 14 to the bottom Where the gas evolves to bubble up through the oil in order to react therewith: After the chemical reaction has progressed to the desired point the gas is drawn off or stopped andthe treater flushed with a diluent. gas which is first dehydrated. When no more of the active gas. or oxygen gas remains in the treater all gas is stopped andthe charge allowed to settle or drained off as desired. The separation of the pure oil and the preci itate can be effected eitherby the use of a lter press or acentrifuge.

4In Fig. 2, which also shows an apparatus for the treatment of petroleum utilizing sulfuric anhydride, the latter is obtained from fuming sulfuric acid in a container 30 provided with a heater 15, the sulfuric anhydride being evolved by heating the fuming acid. In this process dry air is used as a carrier, the air being passed through an air drier 2 and delivered to a line into which sulfuric anhydride is discharged. The exit gases can be absorbedby sulfuric acid in an absorber 50 and then by water, or by water alone in an absorber, forming respectively sulphurous andfsulphuric acid. By using Precipitates are K sulfuric acid as the first absorber, all unused sulfuric anhydride passes into the acid, forming again fuming acid which can be reused for evolving the oxidizing gas.

It will, therefore, be seenthatthe invention accomplishes itsobjects. A vprocess is provided for not only freeing the petroleum of its impurities but'for accomplishing the same in a simple and economical manner. The process enables the employment of standard equipment andlosses are practically eliminated since there is no sludge formed All products are of a commercial value and are not waste products since the precipitates contain products of commercial value such as carbons, waxes, asphaltand even nitrogen and sulfuric compounds which have commercial value. The purified petroleum itself is not only pure but also stable since dehydrogenation has been avoided. Not only can the process be utilized for the purification of petroleum generally but cracking stock can be purified which when afterwards cracked produces products of superior quality, color and without odor. Pure kerosene can therefore be made which is not vtrue where the sulfuric acid treatment is utilized.

It will be understood that the apparatus may be of any suitable and usual construction and detail description thereof has been accordingly avoided. Moreover it will be understood that valve connections are provided where required and these have been generally indicated.l However, those skilled 1n the art wilil know where to place valve connections, etc. Furthermore, while certain theories have been advanced it will be understood that these have been advanced for the purpose of facilitating the disclosure and not as being absolutely essential or necesgsary. Itis, therefore, to be understood that this invention is not to be limited to any particular 4theory of operation. -It is also ob- -vious that various changes\may be made 1n details withoutdeparting from the spirit of this invention; it is, therefore, to be unde-rstood that this invention is not to be limited to the specific details shown and described.

Having thus described the inventlon what is claimed is: .l

1. The process of treating petroleum, comprisin passing therethrough sulfuric anhydri e .maintained in a dry and gaseous V state.

2. The process of treating petroleum, comprising,' assing therethrough dry and lgascous sul uric anhydride while the temperature is maintained above the condensation point of the sulfuric anhydride.

3. The process of treating petroleum, coniprising', passing therethrough dry and gaseous sulfuric anhydride while thevtemp'erature is maintained above the condensation 'point of the sulfuric anhydride and below the dehydrogenationpoint of the petroleum.

5 ing temperatureof the gas.

5. The process of treating petroleum, comprising, passing therethrough diluted dry and gaseous sulfuric anhydride While the petroleum is maintained above the condens- 10 ing temperature of the gas and below the dehydrogena-tion temperature of the petroleum.

6. The process of treating petroleum, comprising, passing therethroug dry and gaseous sulfuric anhydride Whi e the petro eum is maintained above 140 F.

7. The process of treating petroleum, comis I prising, passing therethrough diluted sul- *i uric anhydride maintained in a dry and gaseous state.

lin testimony whereof I aiiix my signature this 1st day of June 1926.

' Y WRreHTW. saar. 

